The present invention relates to a liquid-gas contactor for use with a non-azeotropic mixture refrigerant.
FIG. 2 shows an example of a refrigeration cycle which makes use of a non-azeotropic mixture refrigerant composed of two or more refrigerants such as, for example, R13B1 and R22. FIG. 3 shows the construction of a gas-liquid contactor which is used for changing the mixing ratio of the refrigerants in the non-azeotropic mixture refrigerant.
Referring to FIG. 2, the refrigeration cycle includes a compressor 1, a condenser 2, a first orifice means 3, a second orifice means 4, an evaporator 5, a gas-liquid contactor 6, a cooler 7, and a reservoir 8.
Referring now to FIG. 3, the gas-liquid contactor 6 has a container 9, a connection pipe 10 through which the container 9 is connected to the upstream side of the gas-liquid contactor 6 in the refrigeration cycle, a connection pipe 11 through which the container 9 is connected to the downstream side of the gas-liquid contactor in the refrigeration cycle, lower and upper filler holders 12, 13, filler 14, a gas outlet pipe 15, and a liquid return pipe 16 leading from the reservoir 8.
In operation of the refrigeration cycle shown in FIG. 2, the mixture refrigerant compressed and discharged from the compressor 1 is recirculated as indicated by an arrow and is returned to the compressor 1. During recirculation, the refrigerant discharged from the compressor 1 is condensed and liquefied in the condenser 2 and the condensate of the refrigerant is expanded through the first orifice device 3 so that a part of the mixture refrigerant is evaporated. The gaseous phase of the refrigerant generated in the first orifice device 3 is introduced through the connection pipe 10 to the gas-liquid contactor 6 and ascends through the tiny spaces formed in the bed of the filler 14 so as to flow through the gas outlet pipe 15 into the cooler 7 where it is cooled and liquefied again to flow into the reservoir 8.
A portion of the liquid phase of the refrigerant is returned from the reservoir 8 to the gas-liquid contactor 6 through the liquid return pipe 16 and flows down through the tiny spaces in the bed of filler 14 so as to contact with the gaseous phase of the refrigerant flowing upward through these spaces. As a result, heat is exchanged between the liquid and gaseous phases of the refrigerant, whereby the mixing ratio of the recirculated refrigerant is changed.
Thus, the mixing ratio of the mixture refrigerant recirculated through the refrigeration cycle is varied by the gas-liquid contactor. The range of variation of the mixing ratio is ruled by the performance of the gas-liquid contactor 6. More specifically, the range over which the mixing ratio is changed is increased by promoting the heat exchange through attaining a greater chance of contact between the liquid and gaseous phases of the refrigerant. This can be achieved by increasing the area of contact between two phases of the refrigerant. It is therefore desirable that the gas-liquid contactor is designed to invite a greater quantity of gaseous phase of the refrigerant.
The construction of the gas-liquid contactor 6 shown in FIG. 3 suffers from a problem in that, since the position of the liquid returning pipe 16 leading from the reservoir 8 is offset from the center of the container 9, a local concentration of the liquid phase of the refrigerant tends to occur through the filler bed. This hampers uniform distribution of the liquid phase, with the result that the gas-liquid contact cannot be conducted uniformly over the entire region of the filler bed.
In addition, since the lower filler holder 12 is so designed as to extend perpendicularly to the direction of flow of the gaseous phase of the refrigerant introduced through the connection pipe 10 leading from an upstream portion of the refrigeration cycle, the lower filler holder 12 poses a large resistance against the gaseous phase of the refrigerant entering the bed of the filler 14 through the holes in the lower filler holder 12. In consequence, a considerable portion of the gaseous phase of the refrigerant introduced through the connection pipe 10 is made to flow directly to the downstream side of the gas-liquid contactor in the refrigeration cycle through the connection pipe 11, without entering the bed of the filler. In consequence, the area of the gas-liquid contact is decreased to reduce the range of variation of the mixing ratio.